Trolling motors are used on small fishing boats to slowly and quietly power the boat through the water while fishermen fish from the side of the boat. These trolling motors are generally mounted to the bow of the boat and include a mounting bracket or other arrangement so that the motor may be retracted from the water when not in use. The better and more convenient bracket designs remain fully attached to the motor and retract the motor completely from the water and on to the front deck or bow of the boat. A typical retractor is disclosed in U.S. Pat. No. 3,861,628 and assigned to St. Louis Die Casting Corp., the assignee of this patent application, and which patent in its entirety is hereby incorporated herein by reference.
The trolling motor is generally secured to the retractor by means of a bracket which fastens around the motor shaft and has two swivel mounting points to allow the motor to swivel about the retracting arm members as the retractor is operated. These swivel points can be damaged during the operation of the trolling motor when the motor or its shaft runs into submerged logs or other obstructions in the water. When the motor or shaft comes in contact with an obstruction, a torque is created which attempts to turn the motor and shaft inwardly under the front bow about one of the bracket swivel points. Generally, it is the lower swivel point which acts as the fulcrum and the upper swivel point is severely damaged on broken away from the bracket when this occurs.
There have been various attempts at modifying the retractor to eliminate damage to the upper swivel point. One of these is to provide a shear pin for the upper swivel point which has enough rigidity to withstand rough handling, but will shear if a sudden impact force is applied to the lower end of the motor shaft. However, this solution has several drawbacks which make it unacceptable for general use. It is common for the retractor device to be roughly treated and banged around during operation which may cause the pin to deform and restrict the swivel action at the upper swivel point. To compound the problem, once the pin becomes deformed it cannot be easily replaced as it is usually installed longitudinally through a collar member and a deformation of the pin wedges it tightly in place. Once deformed, the pin cannot be driven through and out the other side to replace it. Conversely, the shear pin may become loose and wobble within its mounting so as to incorrectly position the motor in the retractor and prevent the motor from being retracted onto the bow.
When a pin shears, it must be replaced with a new pin before the trolling motor can be put back into operation. This requires that the fishermen discontinue their fishing, hunt for a new shear pin, and have on hand the necessary tools to install the new pin. Not only is this time consuming, but it is very likely that the proper tools are not available on a fishing boat or that the fisherman has forgotten to bring along a spare pin.
Applicant has developed a design with a spring clip break-away and pin assembly which provides all the advantages of the shear pin but eliminates the drawbacks. The spring clip break-away generally includes one or two flat, yieldable, resilient members which have arcuate sections at their end for receiving a pin. The pin is fixedly secured to a collar which mounts the motor and motor shaft. During normal operation, the pin is held in place between the spring members or between a spring member and a support arm, thus securing the motor to the support arm. When a sudden impact or torque is applied to the shaft of the motor, the pin pulls out from between the jaws of the spring members or from underneath the single spring member, thereby allowing the motor and shaft to rotate about the lower swivel point of the mount. This allows the motor and shaft to be pushed out of the way by the obstruction or log without damaging the motor mount or retractor and with a minimum of damage to the motor itself. After the obstruction is cleared, the motor shaft and mount can be repositioned for use by merely providing a torque against the upper end of the motor which repositions the pin within the jaws of the spring members. There is usually provided means to loosen the spring members so that the pin may be repositioned with less torque than is required to pull it loose.
Applicant's design provides a unique swivel point connection which freely rotates during normal use and yet will "break away" when an unusually large torque is applied to the motor shaft. The spring clip break-away is inexpensive and easily installed on both existing retractors and new retractors. Applicant's device can be more fully understood by referring to the drawings and description of the preferred embodiment.